Displacement of residual nonwetting fluid from porous media

Percolation theory of transport in random composites is used to explain the correlation between the residual saturation of nonwetting phase in porous media after displacement by a wetting phase and the capillary number, this number being a measure of the ratio of Darcy-law viscous force in the wetting liquid to interfacial tension force in curved menisci between the two phases. Statistical concepts of percolation theory give estimates of the length distribution of blobs created when the nonwetting phase loses continuity because of displacement by the wetting phase. These estimates agree with the few experimental data. Simple blob mobilization theory and experiments establish that the capillary number required to mobilize a blob is inversely proportional to its length in the direction of the Darcy-law pressure gradient; this and the predictions of percolation theory account for the observed capillary number correlation.     

Effect of analysis direction on the measurement of interfacial mixing in thin metal layers with atom probe tomography

The accuracy and precision of thin-film interfacial mixing as measured with atom probe tomography (APT) are assessed by considering experimental and simulated field-evaporation of a Co/Cu/Co multilayer structure. Reconstructions were performed using constant shank angle and Z-scale reordering algorithms. Reconstruction of simulated data (zero intermixing) results in a 10-90% intermixing width of ∼0.2 nm while experiential intermixing (measured from multiple runs) was 0.47±0.19 and 0.49±0.10 nm for Co-on-Cu and Cu-on-Co interfaces, respectively. The experimental data were collected in analysis orientations both parallel and anti-parallel to film growth direction and the impact of this on the interfacial mixing measurements is discussed. It is proposed that the resolution of such APT measurements is limited by the combination of specimen shape and reconstruction algorithms rather than by an inherent instrumentation limit.     

Reactions of free chlorine with substituted anilines in aqueous solution and on granular activated carbon

Aqueous HOCl reacted with substituted anilines to form chlorinated derivatives. Some debromination and bromination products were also detected from two brominated anilines. When granular activated carbon was present, many additional products were formed. These compounds fall into several different groups: (1) N-acylation products, (2) N-carbomethoxylation products, (3) N=N dimerization products and (4) deamination and hydroxylation products.     

Wet air regeneration of PAC: Comparison of carbons with different surface oxygen characteristics

Surface oxygen has an important effect on the wet air regeneration (WAR) of powdered activated carbons (PAC) and on the adsorption properties of the regenerated PAC. Virgin and phenanthrene-loaded PACs were regenerated in a bench-scale reactor, and then analyzed to determine surface oxygen content, adsorption capacity, and extent of phenanthrene oxidation.Even though the virgin wood-base (WB) and lignite-base (LB) PACs had about the same oxygen content, the oxygen content of the WB PAC increased more than twice as much as the LB PAC during regeneration. The difference was caused by the larger amount of CO₂-evolving oxides that formed on the WB PAC. WAR reduces the capacity of PAC for p-nitrophenol (PNP). Removing the surface oxides had varying effects on the carbon's capacity for PNP. Also, adsorbed phenanthrene was more easily oxidized on the WB PAC than on the LB PAC during regeneration.     

Molecular dynamics study of anisotropic shock responses in oriented α-quartz single crystal

Journal of Materials Science - This paper presents an investigation aimed at understanding the shock wave propagation response of oriented α-quartz single crystals by using molecular dynamics...     

Experimental Identification and Validation of a Crystal Plasticity Model for a Low Carbon Steel on Different Length Scales

Semisolid processing which has become a well established manufacturing route for the production of intricate, thin-walled aluminium and magnesium parts with mechanical properties as good as forged grades, faces a major challenge in the case of steels. The tool materials must withstand the complex load profile and relatively higher forming temperatures which promote chemical interaction with steel slurries. Thixoforming tools ought to last thousands of forming cycles for industrial application to be attractive. Hot work tool steel dies proved to be entirely inadequate when thixoforming steels. In spite of extensive research on tool materials for the semisolid processing of steels, there is yet no material to fulfil this critical role. The present work was undertaken to explore the potential of a novel CrNiCo alloy as the tooling material in semisolid processing of steel.     

Development and psychometric evaluation of the Yale–Brown Obsessive-Compulsive Scale—Second Edition.

The Yale–Brown Obsessive-Compulsive Scale (Y-BOCS; Goodman, Price, Rasmussen, Mazure, Delgado, et al., 1989) is acknowledged as the gold standard measure of obsessive-compulsive disorder (OCD) symptom severity. A number of areas where the Y-BOCS may benefit from revision have emerged in past psychometric studies of the Severity Scale and Symptom Checklist. Therefore, we created the Yale–Brown Obsessive-Compulsive Scale—Second Edition (Y-BOCS–II) by revising the Severity Scale item content and scoring framework, integrating avoidance into the scoring of Severity Scale items, and modifying the Symptom Checklist content and format. One hundred thirty treatment-seeking adults with OCD completed a battery of measures assessing OCD symptom severity and typology and depressive and anxious symptomology. Interrater and test–retest reliability were assessed on a subsample of participants. The Y-BOCS–II showed strong internal consistency for the Symptom Checklist (Kuder–Richardson-20 = .91) and Severity Scale (α = .89). Test–retest and interrater reliabilities were both high (intraclass correlations > .85). Confirmatory factor analyses did not show adequate fit with previous models of the Y-BOCS. Exploratory factor analysis revealed a two-factor solution generally consistent with the Obsession and Compulsion Severity subscales. Construct validity was supported by strong correlations with clinician-rated measures of OCD symptom severity and moderate correlations with measures of worry and depressive symptoms. Taken together, the Y-BOCS–II has excellent psychometric properties in assessing the presence and severity of obsessive-compulsive symptoms. Although the Y-BOCS remains a reliable and valid measure, the Y-BOCS–II may provide an alternative method of assessing symptom presence and severity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scheme for generating entangled states of two field modes in a cavity

This paper considers a two-level atom interacting with two cavity modes with equal frequencies. Applying a unitary transformation, the system reduces to the analytically solvable Jaynes–Cummings model. For some particular field states, coherent and squeezed states, the transformation between the two bare bases, related by the unitary transformation, becomes particularly simple. It is shown how to generate (the highly non-classical) entangled coherent states of the two modes, both in the zero and large detuning cases. An advantage of the zero detuning case is that the preparation is deterministic and no atomic measurement is needed. For the large detuning situation, a measurement is required, leaving the field in either of two orthogonal entangled coherent states.